Few things in life are as frustrating as running out of juice at the most inopportune times. You need to make an important call just as your phone's screen goes dark. You have to finish an important document just as your laptop's battery runs out. You have your camera poised to snap the perfect shot but when you press the shutter, nothing happens.

PCWorld's latest Superguide, "Extend Your Battery Life," has the tips and tools you need to avoid these hair-pulling situations.

The tips range from the obvious (dim your phone and laptop screens, turn off Wi-Fi when you don't need it) to the unexpected (choose a dark-colored wallpaper for your phone, tweak the screen timeout).

Other sections recommend handy apps and accessories for your smartphone and laptop.